She keeps watching me

It was the same ages for me and my sister. She came to my room one night and asked if I would jack off and let her watch. Apparently one of her friends had seen a guy do that so it was the "girl talk" among her friends at school. I got hard instantly but told her no because we were home and our parents were home. There was a wooded area a few blocks from the house so I told her to meet me in the woods after school the next day and I'd show her. She was fascinated when I came. A couple of nights later our parents went out and she came to my room and asked me if I would do it again. I told her I would but it would feel better and it would be faster is she did it to me. Things took off from there and it wasn't long before we did a lot of touching and oral sex. When she turned 16 I took her out to celebrate and we ended up fucking in the back seat of my car.

I was 17 and my younger sister 15 caught me jerking off one day after school when I thought I was alone in the house.
The next day after school she asked me the next time I did it if she could watch cuz she wanted to see a guy cum before having a steady BF.
The next day was Saturday and I told my sis to come to my room after mom and dad go shopping which they did every Saturday around 10 for groceries for the week.
About 10 minutes after mom and dad took off she came to my room and I told her she could jerk me off and I had to show her how to do it and when I started to cum she actually put her mouth over the head of my cock taking my cum in and eventually swallowed most of it and asked me if she could do it again and was disappointed that I couldn't get hard right away and we started in talking a lot laying on my bed naked together and the following Saturday we ended up having sex together and I came deep in her puss. Since then we have been having sex together about every other day and for a long time when we can. This has been going on now for almost a year. Neither one of us has a steady BF or GF and even if we did that wouldn't change our feelings for one another.

She definitely wants to know..And you to say her name..That you're beating it to her...Wants to know she's hot, you want her body, and you can't handle just looking at her without the need for self-pleasure. Let her watch, and, help.

She wants to know if you're doing it with HER in mind.. Prove to her that you are. My older sister loved catching me in the act and knowing she was the cause.

Turn towards her and let her see how hard you are and then cum for her.

Let her watch and ask her if she wants to join you.